Why did Trump just do that?

Stupid is as Stupid does. He doesn't understand what the government does, nor does he care, so he has no understanding of the impact. He is such a thin skinned tyrant that none of his 'advisors' will tell him no. 

I have a feeling I'll be retyping this repeatedly. 

With No Warning, House Republicans Vote to Gut Independent Ethics Office

So House Republicans plan to "Fix Washington" by getting rid of Ethics Office? Somebody has BIG plans.

More:
http://mobile.nytimes.com/2017/01/02/us/politics/with-no-warning-house-republicans-vote-to-hobble-independent-ethics-office.html